links for 2011-02-17

To know if design changes improved the usability of an application, you first need a baseline measure of usability from a benchmark test.

Here are 10 tips to use when planning your next benchmark test.

1. Recruit for representativeness over randomness: It will be difficult to select a random group of users for your tests. Worry less about the random selection than how well your test users match your entire user-population. If you need to compare new versus existing users or domestic versus international users, it is more important to have these users proportionally represented than trying to randomly select them. Even clinical trials have problems with random selection and most usability tests don't involve life and death decisions.